Multi-disciplinary herbal study – Huang Qi

Posted: 08 Apr 2008 01:32 PM CDT

Last term at NCNM, the Classical Chinese Medicine students in my class took a course with Paul Kalnins, an anthroposophical researcher and natural medicine superstar, about the pharmacology of natural substances. We were asked to write a paper about a particular herb, bringing together Chinese and Western information about it. I asked my class if anyone would be interested in bringing their paper public, and one brave soul took me up on my offer – Danit Polunsky. Below find the results of her research – lightly modified from the original. It’s been a while since I’ve talked about a single herb, so I thought this would be welcomed. I’ll put my paper up next – on Wu Zhu Yu.
Huang Qi: Astragalus Propinquus – aka: Astragalus membranaceu
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Fabales
Family: Fabaceae
Subfamily: Faboideae
Genus: Astragalus
Species: A propinquus
Botany:
Huang qi prefers sandy to loamy soil, which is well drained, or even dry. Huang qi likes soil that is neutral & alkaline, in a sunny location; it will not grow in the shade. Huang qi, Astragalus membranaceus, is an herbaceous perennial with a deep straight tapering taproot.
Each flower has five petals; the banner is large and envelopes the rest of the petals in a bud, often relaxing when the flower blooms. The two adjacent petals are the wings, surrounding the two bottom petals with claws one and a half times the length of the limb. The two bottom petals are fused together at the apex, remaining free at the base and forming a boat-like keel. Together the petals are whorled into a bell shape (calyx campanulate), 8 to 9 mm long, forming a tube 3 times longer than the linear subulate lobes. Each flower is hermaphroditic with 10 stamen, 9 fused and 1 free. They are pollinated by bees, moths and butterflies. Huang qi’s flowers turn into legumes that are 10 to 13 mm long, papery and glabrous. The seeds are dark brown, kidney shaped, and 7 to 8 mm long.
The taproot grows 30 to 100 cm long and 0.5 to 2 (rarely 2.5 ) cm in diameter. It is twisted near the crown, wider at the top, and generally stripped of secondary rootlets. The outer surface is light grayish-yellow to yellowish-beige with longitudinal wrinkles irregularly dispersed throughout horizontal lenticel-like patterns. A cross section of the top portion of root reveals 2 to 3 mm thick light yellowish-white outer cortex surrounding light yellow xylem that look like cracks in larger roots. The root has an overall fibrous texture, making it difficult to break, a slightly starchy aroma, and a starchy, mildly sweet slightly acrid, bean-like taste. Many of the Fabaceae host diazotrophs in their root nodules. Diazotrophs take nitrogen gas out of the air and convert it into a form of nitrogen that is usable to the plant, such as ammonia, nitrate, and nitrogen dioxide, in a process called Nitrogen fixation. Nitrogen fixation is important for replenishing the soil nutrients

Traditionally, the roots of 4 to 5 year old plants are collected in the spring or autumn; the autumn harvest is superior to the spring harvest. In the autumn the qi is descending and internalizing in preparation for winter, which is reflected in the qi of the root herb. The spring qi is emerging upward and outward, striving for growth and spreading from the root into the leaves. After gathering, the roots are cleaned and graded according to size. Some roots are dried whole, while others are cut and sliced. Most authorities report increased potency and increased root size from plants in the Shanxi Province and Mongolia in western northeast China. The Huang qi samples from Shanxi province and Mongolia show high astragaloside I and II concentrations in fingerprint analysis tests.² Comparative chemical analyses of roots of varying age show that the isoflavone and astragloside concentrations, the constituents correlated with activity, decrease as the diameter of the roots increases. Increasing age also correlates to a decrease in concentration of most constituents.
High quality roots are dry, but still supple and resistant to snapping. The outer surface is relatively unwrinkled, with a floury texture and a solid deep yellow core — in contrast to material which is lacking a core or roots in which the core is black or pithy.
Western Perspectives on Huang Qi activity:
Huang Qi is known for three main groups of active constituents. Flavonoids and isoflavanoids, which give the root slice a yellow color, are metabolized on the Shikimate pathway. Flavonoids are generally known for anti-inflammatory and anti-oxidative effects which assist the body’s reaction to allergens, viruses, and carcinogens. It is believed that isofavanoid activity will help restore impaired immune systems. Saponins are common ingredients of Fabaceaea family members. Saponins are triterpenoids, formed through the mevalonic acid pathway. Saponins are common adaptogens, known to enliven blood circulation and resolve phlegm. Huang qi also has long-chain polysaccharides with potential medicinal benefit mediated by white blood cells.
The majority of Western research on Huang qi is focused on its immune stimulation activity and its ability to restore the activity of a suppressed immune system. In an epidemiological study in China, 1000 individuals were administered Huang qi orally or as a nasal spray to test its preventative effects in upper respiratory illnesses. The incidence of common colds decreased on the whole, and the duration of the colds contracted was shortened dramatically.
Huang qi’s remarkable ability to restore the functioning of a suppressed immune system has been labeled within Chinese medicine as fu zheng gu ben, “restore the correct and secure the root.” It is used to enhance non-specific immunity, protect adrenal cortical function during radiation and chemotherapy, and ameliorate bone marrow depression.⁴ Studies report general immune stimulation that include increased stem cell generation of blood cells and platelets, increased lymphocyte proliferation, increased numbers of antibody producing cells, increased numbers of spleen cells, stimulation of phagocytic activity by macrophages and leukocytes, and increased cytotoxicity by natural killer cells.
In the body, Astragalus increases the activities of Th-1 cytokines and decreases Th-2 cytokines. Th1 cytokines protect against intracellular pathogens like viruses and some bacteria, and are implicated in organ transplant rejection and miscarriage. By inhibiting the production of Th 2 cykotones, Huang qi inhibits the defense against extracellular pathogens, but may exacerbate allergies and asthma.⁵
In China, Huang Qi is used widely in treating cancer, both as a primary treatment and as an adjunct to chemical and radiation therapies. Most frequently Huang qi is combined with Chuan Xiong (lingusticum wallichii). In a number of randomized prospective clinical studies of cancer patients using a combination of Huang qi and Chuan Xiong, it was found that breast cancer patients given a combination of these herbs as an adjunct to irradiation treatments showed a decrease in deaths from 1 in 2, to 1 in 10. The exact formulas and ratios are not recorded, and in practice may vary due to individual constitution. In another study of patients with advanced non-small-cell lung cancer, the effectiveness of conventional chemotherapy was compared to the effectiveness of chemotherapy in conjunction with the Huang qi and Chuan Xiong formula. Patients with squamous carcinoma showed a significant increase in survival time averaging 204 to 465 days; patients with adenocarcinoma showed a less significant increase in survival from 192 to 324 days⁶.
Huang qi’s antioxidant activity has been studied in its benefit to the cardiovascular system and has shown improvement in clinical parameters associated with angina, congestive heart failure, and acute myocardial infarct. A number of isoflavonoids have been identified with free radical scavenging activity, and Huang qi’s polysaccharides also report prevention of free radical damage.
A Classical Chinese Medicine Perspective:
Huang Qi’s recorded use dates back to the first century AD in the Shennong Bencao Jing, the Divine Husbandman’s Classic of Materia Medica, in which Huang qi is classified as a “superior herb.” The superior herbs are “rulers…they control the maintenance of life and correspond to heaven. They do not have a markedly medicinal effectiveness. Taking [Huang qi] in large amounts or over a long period of time is not harmful to man. If one wishes to take the material weight from the body, to supplement the influences [circulating in the body], and to prolong the years of life without aging” these herbs should be used.¹ Crude Huang qi extract tested on rats and mice confirm Huang qi’s safety – no toxic reactions or mutagenic effects occurred.
According to the Ben Cao Bei Yao, Essentials of Materia Medica “When used in harmonizing preparations, it tonifies and supplements; in sweating preparations it relieves the surface; in cooling preparations, it drains pathogenic heat; in moistening preparations, it nourishes the yin and blood.”
Wang Haogu, an herbalist of the Jin-Yuan reform period, maintains that “Huang qi replenishes the defensive and, therefore, is a medicinal for the exterior. It boosts the spleen and stomach and, therefore, is medicinal for the center. Since it is able to treat cold damage with the cubit pulse not arriving, it supplements the kidney origin and, hence, is medicinal for the internal.” Through this explanation, Huang qi is seen as a broadly useful tonic ingredient to include in prescriptions.¹⁰
Huang qi’s sweet flavor and slightly warm nature tonifies the Spleen, Lung, and Zheng qi. It aids in replenishing the blood, uplifting yang, securing the exterior and reinforcing wei qi. It promotes growth of new tissue, urination, and suppuration. It circulates qi, reducing edema, and it drains yin fire. ⁸
Huang qi strongly tonifies the yuan qi. It restores both of the Spleen’s major functions; transformation and transportaion of yang qi drawn from the food into circulation via the Spleen’s other function of building new blood. When qi is strong it can more effectively impel the circulation of blood, which in turn helps resolve disease. Strengthening qi to move blood indirectly eliminates blood stasis without injuring zheng qi, as applied in the Bu Yang Huan We Tang: Tonify Yang to Restore the Five Decoction. The chief herb is Huang qi at 120 g, while the supporting herbs are dosed at 3 to 6 g to give the blood an extra, gentle push. ¹¹ It is also often used to assist in recovery after severe blood loss and to promote healing. It is especially helpful from its Lung affiliation in enhancing eliminative functions of skin, especially promoting healing or elimination of non-healing or non-festering chronic sores or ulcerations. ⁸
The five best know formulas utilizing Huang qi are

Formula name

Uses

Astragalus

20 g
30%

15 g
12%

30 g
15%

15 g
16%

30 g
25%

30g

83%